ONE PIECE Episode 174: A Mystical City! The Grand Ruins of Shandora!
Episode 174 of 1180 of ONE PIECE, aired November 16, 2003, 25 minutes. Available with English subtitles and dub where released.
Episode summary
While Robin is looking at some ruins she found, Yama, The Chief Enforcer, attacks her. Yama is easily defeated by Robin. Later, she discovers the legendary city, Shandora.